IOT IN POWER GRIDS PREPARING ELECTRICAL GRIDS FOR TOMORROW'S CHALLENGES - SIEMENS
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IoT
in Power Grids
Preparing Electrical Grids
for Tomorrow’s Challenges
siemens.com/iot-energy-automation
Writing the Next Chapter
of Digital Communication
Ever since the adoption of digital protection relays in the 1980’s, digital
communication in power grids has become commonplace and gradually
evolved over time to meet the growing needs of a more complex energy
infrastructure. With the growing ubiquity of communication infrastructure,
more and more devices are being upgraded to be able to communicate and
thereby form a so-called “Internet-of-Things” (IoT), unleashing a torrent of
innovation that has found its way from the consumer space to industrial
automation, and by now has reached the shores of the energy industry.
But how is IoT different from classic communication schemes and what
additional value does it add in the context of power grids?
Looking back, communication in power grids has evolved along the path of
increasing digitalization from serial protocols (still in use today) to the adoption
of IP networks and integration of interoperable communication standards like IEC
61850. Meanwhile the Internet as the common infrastructure of all-IP-based
communication has seen an explosion of bandwidth requirements as well as
a steep increase in the number of end points connecting to the Internet. While
the first wave of growth was driven by an increasing penetration of humans
gaining access to smart phones, the next wave will be dominated by “things”
(earlier called “machines”) that either produce or receive data in line with their
respective communication requirements.
The spectrum of IoT enabled devices is very wide, ranging from always-on
communication to frequent connects and disconnects with small data payloads
to only haphazard transmission on rare occasions. To accommodate this type of
flexibility in communication, suitable protocols are needed to cover the widest
possible number of use cases – hence the emergence of “IoT” protocols. Before
we dive into further details, let’s take a look at communication in a typical power
grid today.
Unrestricted © Siemens 2020 Page 1
White paper | IoT in Power Grids v1.2 | Mar 2020 Contents Since 2018 we at Siemens Digital Grid have begun to add IoT communication functionality to our substation automation and protection portfolio, thereby enabling additional data flows from the field- and substation automation level. The benefits of this new capability will unravel as electric grids experience increasingly dynamic situations, empowering our customers to gain deeper insights into what is going on in the grid using combined cloud and edge data processing solutions. With the latest functional upgrade based on SICAM GridEdge, our entire fleet of protection relays covering SIPROTEC 5, SIPROTEC 4, Reyrolle as well as SICAM A8000 RTUs, PQ Devices SICAM Q100/200 and even IEC 61850 enabled 3rd party relays will gradually be supported for integration into the Grid Diagnostic Suite. This Whitepaper outlines the basic motivation behind IoT in Power Grids and elaborates on some of the benefits as they can be discerned at this early stage. Table of Contents Data and Communication in Power Grids ......................................................................................................................... 3 IoT in Power Grids ........................................................................................................................................................... 5 1. Data Semantics .............................................................................................................................................................. 5 2. IoT for Energy Automation Systems ................................................................................................................................ 6 3. IoT for Industrial Power .................................................................................................................................................. 7 4. IoT for Secondary Distribution Automation ..................................................................................................................... 8 IoT Platform Options ..................................................................................................................................................... 10 IoT and Cyber Security................................................................................................................................................... 11 Abbreviations ............................................................................................................................................................... 12 Unrestricted © Siemens 2020 Page 2
White paper | IoT in Power Grids v1.2 | Mar 2020 Data and Communication in Power Grids In the classic view of the power grid, there are essentially three tiers of control: • The field device level • The substation level • The control center level Image 1: Data Processing Layers in Power Grids Unrestricted © Siemens 2020 Page 3
White paper | IoT in Power Grids v1.2 | Mar 2020 The field devices (IEDs) are located near the process and collect their input data from instrument transformers, hence they are the most productive sources of data in the overall architecture. IEDs communicate among each other to enable low- latency operations, as well as with the next higher layer, the substation automation level. Here a small configurable subset of data (approx. 15%) from the field devices is accumulated – still within the context of a single substation. To manage power flows across the entire grid, the control center is the central point for Supervisory Control and Data Acquisition (SCADA System). On this level, only a few relevant data points from all substations in a grid are accumulated via RTUs (Remote Transmission Units), analyzed and acted upon to maintain a stable energy supply. Within this well-defined context, standardized communication protocols like IEC 61850-8, DNP3.0 as well as the classic IEC 60870-5 family have served us well to monitor and control energy automation systems and will continue to do so. Yet the landscape of energy generation, transmission, distribution and consumption has become more sophisticated and will gradually develop into a structure as outlined in Image 2. While previously energy was generated at a few central locations, distributed energy generation with a strong focus on renewables as well as energy coupling between multi-modal grids has become a clear trend in the industry, thus requiring enhanced transparency and data processing capabilities in the distribution domain to maintain a reliable energy supply. Factoring in all these changes, obviously there is a greater need for communication among all participants in the energy infrastructure. Perhaps the biggest paradigm shift in the new age of the “Internet of Energy” is the greater interdependence of all parts of the grid. In the old world, usage of data was restricted to the immediate hierarchy of the grid – in the new world, data from one corner of the grid may be needed to influence decisions outside of its classic “reporting line” – and include operational as well as non-operational types of data. Welcome to IoT communications! Selecting one of the many available options for communication of things means finding a good trade-off between performance, scalability and ubiquity. Below are some key points that guided us in our decision-making process on how to implement IoT in Power Grids. Image 2: Structure of Future Power Grids Unrestricted © Siemens 2020 Page 4
White paper | IoT in Power Grids v1.2 | Mar 2020 IoT in Power Grids As we deal with huge quantity structures of “things”, not all data can be sent at all times from all data sources to all receivers. As a first step it is essential to define a scalable architecture between the bottom and the top layers of the data pyramid – so we chose to adopt a publish-subscribe based communication model. This approach delivers many benefits, a few of them listed below Image 3: Publish Subscribe Architecture Independent decoupling and scaling Through the publish-subscribe mechanism, sender nodes do not communicate directly to receiver nodes but go through a broker node instead, a task performed by our SICAM Grid Edge. In this fashion senders and receivers are decoupled and can operate and scale independently from each other. Nodes on either side of the broker can be added or subtracted without an impact on the overall communication system or a need for complex engineering procedures. Elimination of Polling Publisher nodes operate in a push-based mode and do no longer need to be actively polled from communication back-ends. Data is sent on immediately after measurement values are received. Simplified Communication The system no longer needs to maintain a registry of peers with compatible data types. Instead, messages are classified by topics which in turn can be subscribed to without knowledge of the originating publisher node. 1. Data Semantics Beyond solving the network capacity problem, once a large number of distributed nodes in a widely dispersed network start sending their data, the implementation of proper data semantics is an essential prerequisite for the proper usage of data analytic methods. Each data point needs to be described with all essential attributes like device of origin, physical location, topology position, time stamp, measurement type, measurement value etc.. Only when the semantics are well-defined and openly accessible, it becomes possible to achieve cross-vendor interoperability and hence a wider adoption. To this end we picked the evolved version of the well-established OPC UA standard named OPC UA PubSub (MQTT), which as the name suggests wraps the classic OPC UA payload inside an MQTT container. Furthermore, by also adopting and actively contributing to the related OPC UA 61850 companion specification we get both – a mature data semantic model together with a scalable publish-subscribe architecture. Unrestricted © Siemens 2020 Page 5
White paper | IoT in Power Grids v1.2 | Mar 2020
By supplementing the traditional communication paradigms in power grids with IoT communications, new opportunities
gradually come to light that add additional customer value. To capture this value, a range of applications within the
framework of our Grid Diagnostic Suite 1 were introduced, addressing three different application scenarios:
• IoT for the energy transmission and distribution domain
• IoT for industrial power applications
• IoT for secondary distribution automation
2. IoT for Energy Automation Systems
Digital communication inside a substation is of course not an innovation by itself. Our idea of IoT within this context
however makes a great difference in the way the data is handled. First, we aim to look at a much bigger slice of data in
relation to what is normally available on a substation automation or control center level. Second, we do not require any
additional complex engineering. IoT for our customers should be as easy to deploy as plug & play and offer new
functionality without any impact on an operational FAT/SAT approved substation. The essential features of a substation
automation and protection system are to quickly and selectively trip circuit breakers in case of electric faults, execute
configured switching sequences and report specific threshold violations and alarms. With the help of IoT and the
corresponding bigger data space we are now able to expand this functionality to also recognize slowly evolving trends and
anomalies in the grid that would not necessarily trigger any of the classic responses. Thus, we are now enabled to alert
a grid operator ahead of time and avoid further degradations in the grid.
Our first application that demonstrates the new possibilities of IoT is our SIPROTEC
Dashboard, enabling a grid operator to get a quick overview on the status of his entire device
fleet deployed in multiple substations across the grid, including alerts on operational and
security events.
Furthermore, IoT also facilitates the automatic aggregation of data that was previously hard to
access like fault records, fault logs and alarm lists from across all substations to analyze events
SIPROTEC Dashboard in the context of the entire grid, eventually enabling features like multi-ended fault location
in the Mindsphere Store and a sequence-of-events analysis to determine the actual root cause of a grid event.
Image 4: Screenshots of SIPROTEC Dashboard
1 http://www.siemens.com/iot-energy-automation
Unrestricted © Siemens 2020 Page 6
White paper | IoT in Power Grids v1.2 | Mar 2020
3. IoT for Industrial Power
While most Internet of Things use cases are commonly associated with applications in the context of Industry 4.0,
the benefits of systematic energy monitoring, power quality tracking and long-time data storage in the cloud continue
to become clearer. (see brochure “Power Quality in Production” 2 )
To address this problem space, we offer the PQ Advisor Premium, which is the first solution
on the market that combines these three components in one package. Leveraging on the
advanced features of our power quality devices like the SICAM Q100/Q200, the PQ Advisor
Premium not only tracks energy consumption of individual production lines, but also monitors
power quality indicators like the presence of harmonics or the dynamics of power factors over
time for entire fleets of PQ devices installed on multiple sites. A wide range of visualization
methods combined with data analytics help to correlate the synchronous time-series data from
PQ Advisor Premium a distributed set of data sources and identify possible sources for power quality degradation
in the Mindsphere Store before they lead to defects in sensitive electronic equipment.
Image 5: Screenshot of PQ Advisor Premium
2 http://www.siemens.com/download?DLA03_2150
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White paper | IoT in Power Grids v1.2 | Mar 2020
4. IoT for Secondary Distribution Automation
Outside the substation context, IoT connectivity enables previously silent stand-alone devices
to communicate through wireless cellular or LPWAN networks, e.g. to aggregate data from
classic fault sensor indicators (SICAM FSI) over a wireless communication gateway (SICAM
FCG) into a cloud application to determine fault locations on overhead lines in distribution
grids, as realized by our SICAM Localizer.
Another use case addressed by our SICAM Navigator is the remote monitoring of cable-based
SICAM Localizer secondary distribution substations that are otherwise only inspected manually by service
in the Mindsphere Store technicians.
SICAM Navigator helps to detect and locate faulty segments in medium and low-voltage cable
grids, monitors load profiles and detects various operational anomalies such as phase
unbalances and rapid load changes. This additional degree of transparency will increase in
importance as more and more electric vehicles will enter the market and need to be charged
using existing grid infrastructure.
Yet with all these data flows scaling up in the grid – where is all that data supposed to go?
SICAM Navigator
in the Mindsphere Store
Image 6: Screenshot of SICAM Localizer
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White paper | IoT in Power Grids v1.2 | Mar 2020 Image 7: Screenshot of SICAM Navigator, Station View Unrestricted © Siemens 2020 Page 9
White paper | IoT in Power Grids v1.2 | Mar 2020 IoT Platform Options One great benefit from the adoption of open standards for the communication layer is the freedom of choice when it comes to the decision for the most suitable IoT platform. While many of the available commercial cloud platforms today will be able to deal with the raw data streams as such, the key decision point for a customer lies in the overall user experience. Some points stand out to consider: • Easy scalability for future add-ons of communication nodes • Automated workflows for secure commissioning and operations of IoT devices • Full semantic description of IoT data • API for customer specific application development Grid Diagnostic Suite Application Demos The Grid Diagnostic Suite was developed to create the best possible user experience for IoT grid applications, hence we built our solution on MindSphere as the key cloud platform from Siemens for Industrial Data Analytics. As the amount of actionable data-in-motion keeps growing, it is no longer economically feasible to send all data straight into the cloud. Therefore, we have introduced the SICAM GridEdge to create a multi-layered communication architecture, where the substation edge nodes are capable of ingesting local high-frequency data streams and only transmit relevant bits of pre-processed data into the cloud. One key concern when it comes to large scale IoT deployments is of course the overall topic of cyber security. Considering the growing threat of cyber-attacks on critical infrastructure – how can we guarantee rock-solid operations in all parts of the grid? Unrestricted © Siemens 2020 Page 10
White paper | IoT in Power Grids v1.2 | Mar 2020
IoT and Cyber Security
Regarding Cyber Security, the best recipe for success is a combination of well-tested and
professionally implemented industrial standards like IEC 62443-2-4 and IEC 62443-3-3
combined with usability-centered workflows.
The security architecture is based on a X.509 public/private key infrastructure using
digital certificates to establish trusted relationships between nodes in the grid. All users
Cyber Security and devices that participate in grid communications must be authenticated, their scope
in Energy Automation Products of actions limited to an authorized set of access rights and data flows be encrypted by
default.
The challenging part here is to rigorously apply all these principles to a network with
a vast number of devices without creating complex manual workflows during
installation or an excessive burden on the IT admins during operations.
Within the context of a substation, SICAM GridPass greatly facilitates the automated
Cyber Security enrolment of new devices, including the distribution of digital certificates and the
in Systems and Solutions central administration of role-based access rules 3.
On the IoT platform level, a similar functionality is essential to provide our customers
with a seamless experience – the first concepts for such a solution already exists
in the form of cascaded entities of SICAM GridPass nodes, where each one can handle
allotments of up to 10.000 clients.
In summary we are convinced that the gradual adoption of IoT will increasingly add
Operational Security value to the energy automation domain and shape its future towards a more responsive
and flexible energy grid.
Image 8: Cyber Security Solution Modules addressed by SICAM GridPass
3 http://www.siemens.com/gridsecurity
Unrestricted © Siemens 2020 Page 11White paper | IoT in Power Grids v1.2 | Mar 2020
Abbreviations
FAT Factory Acceptance Test
IoT Internet of Things
LPWAN Low-Power Wide-Area Network
OT Operational Technology
PQ Power Quality
SAT System Acceptance Test
Siemens 2020 For the U.S. published by
Siemens Industry Inc.
Smart Infrastructure
Digital Grid 100 Technology Drive
Humboldtstrasse 59 Alpharetta, GA 30005
91459 Nuremberg, United States
Germany
Subject to changes and errors. The information given in this document only contains
general descriptions and/or performance features which may not always specifically
reflect those described, or which may undergo modification in the course of further
development of the products. The requested performance features are binding only
when they are expressly agreed upon in the concluded contract.
© Siemens 2020
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